Drill-bit.



G. A. HUMASON.

DRILL an,

APPHCATION HLED MAR. 19. I918.

Patented Dec. 30, 1919.

@wawsufi AmJml sow, a wm jam 4?. $22M I the well linown ro iary.

'which is given in GEANVILLE'A, HUMASGN,

' Ji aw-15:1

To aZZ whom maypmam:

Be it"knewn that-1', Gemvmm 1. Kane SON, a, citizen of the Uiiiieel. Limes- -reei. dat Shreveport, in the meat}? eijfie'flele State Louisiana, we im'elioeii new and useful Improvemenss in llriil-Eiis, of which the fellewing is 'eeieetie This 'in i ention r improvements in a v The object of the in? & bit-of the clmraeier especially wa m fez ill? rotary process.

In drilline' by the misty preeess, e drill stem is new which ism-bated by means To the lower end of this stem the, bit is aims-heal usually by means of a drili shank, one end. 03? which is threaded onto iiie .lewer ezaci ef the drill stem aiid intotiie a 3i and (if iviiieii the shank of the hit is the fled. The bit. in use/ and replacei as the must often be i'eiiie i'e same must ofien slim-penal; xm';

more said bit subjected. rs-iii; Si in lling izhreugn e so .U the tni-eacls-un'ilie Ella! is the corresponding seenv become i731; the, becomes c. the stem; the bit 15:1 li i-ateci thereifi'o-iii time eniiieiy er Inililil'g}; the rlrl I is the abject if this rte PEU- vicle an inipl'oveelliomi oi the viii and whereby the bit may be securely attached to the drill stem, s0 that will be no liability of the bit becoming lOOSeZlenli when. the drill stem is rotated beclzwarclly er on account of ihe Wearing 0: the isin'eacls by means of which the bit is sec'iir-eii in said shank.

l il' Ju i A further fee-Lure 0f the inveeilien resides in theproviswn of 2,: his; which may be pliimliiy 0f cietachable provided with m i-ace by mews of blacles securely lieicl. said shank.

"With the above and other ebjecis in View, the invention has particular relation is certain novel features 0% eqi'lstmction, an" rangement of parts ami use, an exampl 01" this speeii'icniion my 1 1 z I 4 l aeep Well willing by which 8 extefieiisy iiireeiieii 01 a bte'sli ieeve 5, said she; accompanying drawings v eetieiiei View teiien line 01: Fig, 2, and Li Refermz g new more partlculai ly te the:

imwings' Wllfil'QElfl like numemlsei reieyeiice designate similar parts in eeeh of the figures, the numeral 1 refers to a "chill stem, the-la yer end 0f which is tliremied irate the upper end of the chill shankfi. The lewer end of tliis shank is enlarged, ferming an abrupt annular sheulfler 3, ami an eiilgirged head willy threaded to receive the sleeve 5. upper end 0?? this sis/eve is cylincli'ieal in shape, mended of? at theiowe'r end, ami is contracted to foam an annular flangev 6, Lllfi upper end of? this drill slumnt 2, and rests" 219011 die annular EliQfllilG-l The numeral 7, iefei s 530 an ixmi'y fish-tail 'blecie which has l1e upper :50 the lOWBE" eml. ii-ejecting 9; sufieient ziiszsnee dawnwm-(liy mm the lies Pi 4 this purpese. The i has a tmnsvei se mertise cut eieiglireugli, the upper 112111503 which is en :Ug l, as at 10, {mining im approximately ey-lmle sliepel slot ilnfouglirtlie lies-Cl 1negral with the shank of the blade zind pmr therefrom is a ienen 11,

gecting upwardly which snugly 111 said mortise, thus clove tailing the blade into the drill heziei; The

'zenon 11 thus receives the strain due torota ti m and relieves the thread on the drill Link ilieiesf. The ordimry fish-tail bit 3 provided wiizli eniy twe blades, but ad- (liiienal blades, as 12, maybe provided if desired. In case additional blzieies are provided, tlieyere snails detachable, and-are fitted into vertical greoves sides of die shank 8, saicl blades being provided with ienens 1%, shaped like tenons l1, pz'evmusly (lescribei, and which are fitted into mortises 15, extending radially wvitli reference to the inertise The head 4- is exter- The 13-, in oppesi'te The sleeve 5 fits blades 12 securely in. place. i

In attaching the blades to the drill head,

the te'non ll is brought into alinement with the mortise 9, and moved laterally until it is seated therein; The sleeve 5; is then fitted over the upper end of the drillshank and. screwed down over the enlarged head a, and

' the shank 8, of the blade, thus securing the same in position and locking the tenon in the mortise. In case additional blades, as 12, are employed, before screwing down the sleeve ,5, these blades are seated in the grooves 13, and the tenons 1% are seated in the corresponding mortises 15 of the head 4, and the sleeve. 5 is thcnscrewed down over the shank 8, thus locking said detachable blades 12 securely in position.

In the modified form shown in Fig. 2 the upper portion of the head 4 and the corresponding portions of the tenons 14, as wel as the o )posite )ortion of the sleeve 5 are left blan The i fitting together along the transverse plane indicated at 17, so that in case the tenons locking the blades to the head 4 should break, the head'will be permitted to rotate, in the sleeve 5, but the flange 6 will lock the lead is in two sections bit against detachment-from the stem sothatthere will be no possibility of the bit becoming lost in the bore.

Water down through the shank 2, issuin from the lower end of the head through w ich water flows from the interionofthe drill stem to the cutting points so as to flush the bore and carry away the cuttillgs from the bit. \Vhat I claimis: 1 l

In a rotary drill, a shank, an enlarged head on the lower end thereof, a mortise therein, a shoulder on said enlarged head, a

passageways 16, 16,'are provided flat blade fitting in said' mortise in said head, j

a sleeve fitting over said shank, and hav; ing a threaded corirfection Jvith said blade, and an inwardly extending flange on said sleeve-fitting over said shoulder whereb the blade is secured against detachment'tli from.

In testimony whereoef I have signed my name to this specification in the presence of I subscribing witnesses.

ere-

GRANVILLE A. HUMASON.' g

Witnesses v E. V. HABDWAY, E. B. BIERCE. 

